Automatic overload clutch



March l2, 1929.

E. ERMOLD 1,705,047

AUTOMATIC OVERLOAD CLUTCH Filed April 2, 1927 2 Sheets-Sheetl l INVENTOR /a ATTORNEY Mmh 12, 1929. E. ERMOLD mam? AUTOMATIC OVERLOAD CLUTCH Filed April 2, 1927 2 Sheets-Sheet 2 N l @gm B l y 1 me si N N W l INVENTOR I Q Efiqwmwwfd L 1,705,041 PATE EDWARD Eamonn, or NEW Yoan, my.

AUTOMATIC ovEaLoAncLU'rcH.

Application inea Aprii'z', 1927. serial-mi. 180,437.'

lThis invention relates to an automatic over load clutch, and has for its primaryvob]ect I -to provide simple and eiective means autof matically operative when an overload is placed upon a machine to disconnect the machine from afpower actuated driving mem ber, and thereby prevent possible in]ury to the mechanism.

More particularly, the invention has for an important object to provide an improved mounting and arrangement of a movable clutch member upon a driving gear or sprocket for cooperation with a complementaryv clutch part on a driven member lwhereby power is transmitted to the machine to be actuated to normally connect said driving and driven members for rotation as a unit, and

additional means on the driving wheel for' retaining the clutch member in its releasing position to permit of independent relative rotation of the ldriving wheel or gear and -tlie driven gear. i f y l It is also a further object of the invention to provide an automatic safety clutch of the above character which is simple in the oo nstruction and relative arrangement of' its several parts, positive and reliable in its op- .eration and ma beic'onstructed and applied to various mac ines `atcomparatively small cost. l

With'the above and other objects in view, the invention consists in the improved automatic overload clutch and in the form, 'construction and relative arran ement of itsy several parts as will be liereina ter more fullydescribed, illustrated in the accompanying drawings, and subsequently incorporated in the subjoined anim.

characters designate .corresponding parts 'f -sure' of the clutch element or-rol er 17 upon the liange 1 0 of the driven gear 7'. This end 'of the lever 13 is also provided on the -inner -In the drawings, wherein Il have disclosed one simple andpractical embodiment of the invention, and in which similar reference throughout the severa1views,-

, Figure 1 is a sectional y 'ew taken substan-l tially on the line 1-1 of Fig. 3, showing' the driving member or -gear provided withmy improved clutchl means showing the latter in its normal sition; Fig. 2 is a similar view, 'showing the mov able clutch member in its released position; Fig. 3 is a longitudinal sectional view taken substantially onl theline 3-13 of Fig.v4

1, and r. l

Fig. 4 is a sectionalview on a reduced scale taken on the lline 4-4 of 3.

Referring in detail tn the awings, 5 des,-

ignatesa shaft or arbor suitably mounted l and ri idly fixed in the frame structure in- .i

dicate .at 6. Upon the Shaft 5,the driven gear 7 is loosely'mounted, said gear adapted for meshing engagement with a powerv transmission gear of the machine to be op' i erated, such transmission gear being indi- 2 of thegear 7' is formed intermediate of its vends with a flange 10 which is provided inU-its periphery at suitably spaced points with the' recesses or seats 11, the purpose of which willy hereinafter a pear. f

Upon the end of the ub extension 9 of and is adapted to be suitably connected with amotorv or other convenient source of power.

Upon one side of the gear wheel 12`and ad-L ]acent its outer edge the lever 13'is pivcated intdotted lines at 8. A hub-extension i0 .the driven gear 7 a drivingv gear or` sprocketwheel as indicated at 12 isvlosely'mountedf otally lmounted yat one'ofits ends as at 14.

Tothis'lever intermediate of its ends a pin ri l or `stud 15is suitablyv fixed and entends f throii h aradially disposed fslot or opening 1 6 in t e weblof the wheel 12. Upon the other end of this pin 15 the roller 17 is rotatably mounted and is adapted for seating'engagef ment in any one of the recesses 11V in the ange 10. .In spaced relation to. this pin 15, the ever 13 is vprovided'virith a slot 18 concentric witli the pivot 14 to receive the. pin or stud 19 ixed tothe wheel 12. the other end .of-the'lever 13 one end .of a coil spring 201s suitablyattached, the other end of said spring being connected to a memide t ber 21 adjustably mounted in a bracket 22 fixed to the wheel 12, said member having a ing nut 24 bearing against one side of said bracket is'engaged. By adjustment of the lmember 21, the tension `of spring 20 can be 'regulated so as to maintain the re uisite pres.

edge thereof with acam surface indicated at 25 and with this surface, the finger 27 28 -projectingfrom the opposite side ofthe 30 is attached,`the other end of said spring being, secured as at 31t0 the wheel or ear 12; 'A stop screw or pin 32 fixed to said w eel isv adapted for engagement by the arm 28 Ato'limit the pivotal movement of the dog 26 under theaction of the spring 30,

ythreaded shank 23 upon whichthe adjust# 'l ioor Assuming that the parts are in the position shown in Figs. 1 and 3 of the drawings,

it will be evident that when the driving member 12 is rotated, the clutch member 17 being held in one of the seats l1 by the spring 20, the driven member 7 is rotated as a unit therewith to transmit power through the ear 8 to the machine. Should an overloa -be placed upon the machine being operated so as to retard rotation'oi:l the driven gear 7, as the driving gear 12 is being rotated at a relatively higher speed, the clutch roller 17 will instantly ride out of the seat 11 in. ange 10 and with the addition of the centrifugal force dueto the location of pivot 14, the ac.

tion of spring 20 is overcome, the lever and clutch roller moving to substantially the position shown in Fig. 2 of the drawings. In this movement of the lever, the Hnger 27 of the dog 26 rides upon the lcam edge 25 of the lever and beyond the same, the spring 30 contracting until the arm 28 engages the stop pin 32 and the finger 27 is positioned substantially at right angles to the edge of the lever. Thus, this dog holds the clutch lever and roller in the position shown in Fig. 2v

against the contracting action of spring 20 so that the driving gear or Wheel 12 may continue to rotate freely relative to the driven gear 7. By thus automatically disconnecting the machine being operated from the driving gear, the possibility of serious damage to the gearing in the case of overload being placed upon the machine is avoided. When the dog 26 is returned to substantially the position of Fig. 1, the spring 2O immediately contracts so that the clutch roller 17 again bears on the' flange 10 and in the rotation of the gear or wheel 12 will seat in one of the notches or recesses 11 to thereby again connect said driving gear with the driven'gear 7.

From the foregoing description considered in connection with the accompanying draw'- ings, the construction, manner of ,operation and several advantages of my improved auto matic safety overload clutch will befclearly and fully understood. Itwill be apparentthat such a device is readily adaptable for use in .connection with the: drive lgearing for various different kinds of machines and is vpositiveand reliable in its action to effect the disconnection of the machine from the driv-l ing 'gear upon the occurrence of an overload. I ave shown a mounting and arrangement of the several parts of the clutch in connect tion with the driving gear which I have found to be reliable and satisfactory in practical operation.y Nevertheless, it will be understood that the form, construction and relative arrangement of the several elements em ployed might be suitably varied, and I therefore, reserve the privilege of resorting to alla such legitimate changes therein as may be fairly embodied within the spirit and scope ofthe invention as claimed.

I claim:

In a power transmission mechanism, the combination of a' driven member and a driving member, one of said members having a hub formed at its periphery with a curved 70 notch, and the other of said members having a web formed with a guide slot; a main lever pivoted atone end to the web; a roller rotatably secured to said main lever intermediate the ends thereof; a guide member secured to 75 the lever and projecting through the guidev slot of the web; a spring attached at onev end to the web and at its other end to the main lever, for normally holding the main lever in a position with the roller engaged in the. Se notch, but adapted to ield when an excessive torque is encountered between the driven and driving members to permit the roller to ride out of the notch; a latching .lever having an 'inner and an outer arlnfsaid latching lever 85 being pivoted intermediate its arms to the Web, theinner arm being adapted tomove under an end of the main lever when the main lever is moved to a position with they roller out ofengagement with the notch, to lock the main lever in such position, the outer arm of the latchinglever being adapted to aiord suficient leverage to facilitate releas- A ing the latch from locking position; a spring having one end connected to" the louterarm vo :f the latching lever and its other end connected to the web; and a stop for limiting the movement of the latching lever in Vone direction.

-- In testimony that I claim the foregoing as 1G43 my invention', I have signed my name hereto EDWARD ERMOLD. 

